Homework Statement
The problem is basically a fair ride that has a pole as its base, another pole sticking out of it, the a cable with a chair at the end. I am given the length of the rod sticking out (3.00 m), the cable (5.00 m) and the angle between 30.0\circ. I have to find the time it takes...
Homework Statement
A 90 kg metal slab is pulled across the ground by a tractor. The coefficient of friction between the slab and the ground is µ = 0.65. If the force of the tractor on the slab is 600 N and is directed at 35° from the horizontal, what is the acceleration of the slab...
Homework Statement
Find the speed of a particle whose relativistic kinetic energy is 40% greater than the Newtonian value for the same speed.
Krel = relativistic kinetic energy
Knew = Newtonian kinetic energy
Homework Equations
Krel = (gamma - 1)mc^2
Knew = 0.5mv^2
gamma =...
Apparently things like the Lorentz' force can't be handled as a hamiltonian system. I heard other people describe the hamiltonian mechanics as an equivalent characterization of classical mechanics, but this is wrong, then?
Homework Statement
If you poke a hole in a container full of gas: the gas will start leaking out. In this problem, you will make a rough estimate of the rate at which gas escapes through a hole: effusion. (This assumes the hole is sufficiently small).
Consider such a hole of area "A". The...
From what I have learned so far, it appears that a light emission orthogonal to motion acts exactly like a Newtonian massive particle with conserved longitudinal momentum. Is this correct?
If so it would seem to be a cosmic coincidence of monumental proportions.
Having given it some...
Hello. I've recently been working on the mathematics of atmospheric/stellar density, but I've run into an apparent paradox with the assumptions I have been using. I hope this is the right forum for this question.
At the moment, I'm working on the equations for the atmospheric pressure/density...
A very simple way to explain the observable universe expanding:
Perhaps there is just a bunch of matter surrounding the observable universe and all the observable stars/galaxies are moving per the gravitational field created by matter outside that we have not yet seen. Thoughts?
This paper, written by a University of Pittsburgh professor, John Norton, describes a simple situation in which Newtonian mechanics allows for purportedly non-deterministic equations of motion:
http://www.pitt.edu/~jdnorton/papers/DomePSA2006.pdf
In the first part of the paper, he describes the...
Last week there was a documentary program on Nat Geo I believe having to do with the composition and origins of comets. The narrative seemed to imply that comets originate within & are rather randomly dislodged from a spherical shell around the Solar System called the Oort cloud. This...
I would like to calculate pressure drop rate across a valve,...
Material is a "non-soluble" polymer melt dispersed in water...When the solution is released at high temperature from a valve I would like to calculate pressure drop rate...
Question is should we be using non-Newtonian...
Actually i never got this concept clearly in my mind. What is the meaning whern we say that the energy of a body is negative? For example in Bhor's atomic model we have calulated the total energy of an electron to be negative. Please explain me by using Newtonian Mechaincs as i am the...
I don't have the books in front of me so I only use my memory. According to my professor and if I remember well, Landau and Lifgarbagez, the Lagrangian of an isolated particle can in principle depend on \vec q, \vec \dot q and t. Therefore one can write L(\vec q, \vec \dot q , t). With some...
Hey guys,
Was wondering if anyone has seen this done? Essentially I've tried plugging in the Schwarzschild exterior metric and getting a radial wave equation then taking a series expansion for small M (gravitating mass) and comparing that to the KG radial wave equation in a radial potential...
I'm still on special relativity, and haven't yet reached general relativity, but had a question in mind...
does the Newtonian description of Gravitational Potential Energy
U= -G \frac{M m}{R}
fail for very strong gravitational fields?
or it only fails where curvature of space becomes...
Homework Statement
Hi Guys,
I am hopeful someone here may be able to help with this but if people think this should be on a different forum please let me know and I'll move it.
I am writing a computer game and I am currently working on the computer controlled player. The player is a...
I've been told for many years now that the speed of Newtonian gravity is infinite. However, I've never received an explanation (or derivation) as to why this is that completely satisfies me. Even the explanations in textbooks (e.g Hartle) seem lackluster to me. So let's see...
The field...
Homework Statement
a man with mass m=66kg is standing on top of a platform with mass M=120kg. The man is pulling himself up using a pair of ropes suspended over massless pulleys. he pulls each rope with force of F=600N and is accelerating towards the ceiling at acceleration a. g=9.8 m/sec^2...
Homework Statement
A 2.0 kg block rest on a 4.0kg block that is on a frictionless horizontal table. The coefficients of friction are u_s = 0.3 and u_k = 0.2. What is the maximum force F that can be applied to the 4.0 kg block if the 2.0 kg block is not to slip? If F has half this value, find...
Homework Statement
1.The work required to lift a mass one meter depends on the speed at which it is raised..
2.The acceleration of an object is same in all inertial reference frames.
3.A particle's kinetic energy can change without having any net work done it.
4.The work done by...
(Moderator's note: thread moved from "Differential Equations")
A parachutist whose weight is 75 kg drops from a helicopter hovering 2000 m above the ground and falls towards the ground under the influence of gravity. Assume that the force due to the air resistance is proportional to the...
(Moderator's note: thread moved from "Differential Equations")
A particle of mass m which moves along a horizontal straight line with a velocity of v encounters a resistance of av + b(v^3), where a and b are constants. If there is no other force beside the resistance acting on the particle and...
Understanding the short-distance behaviour of gravity is crucial for constructing a quantum theory of gravity. The Newtonian inverse square law approximation has been tested in laboratory down to millimeter scales, but I'm not aware of any laboratory scale experiments testing general...
hey everyone
I'm in year 12 physics, and we have a project revolving around the physics of sport
i selected golfing, and my initial aim is to investigate the inaccuracy associated with predicting the aerodynamic motion of a golf ball (max height, max distance).
i selected this mainly...
Hey guys,
Im trying to derive the following equation
(mc^2) [(1/E2)-(1/E1)]+cos(theta)-[((E1-E2)^2)/(2E1E2)]=1
E1 = Incident Photon's energy
E2 = Scattered Photon's energy
theta= scattering angle
m = mass of electron
c = s
Using conservation of energy,conservation of mass, and...
Homework Statement
Derive the equation non-relativistic equation for Compton scattering
(mc^2) [(1/E2)-(1/E1)]+cos(theta)-[((E1-E2)^2)/(2E1E2)]=1
E1 = Incident Photon's energy
E2 = Scattered Photon's energy
theta= scattering angle
m = mass of electron
c = s
Here is the lab
In...
Hello all,
First and foremost, I want to apologize if I am posting in the wrong area. Please inform me if so.
I am new to the forums (hence my first post), and will be doing my first Physics course this winter (starts after New Years) since 2002. I really need to do well, and I have the...
I thought of this problem recently and I was amazed at how difficult it was to solve, given the simplicity of the statement of the problem. I still have no idea how to solve it. The problem is thus: two point masses of 1 kg each are spaced 1 meter apart in a vacuum in space, with no other forces...
In what situations do Newton's law of universal gravity fail to predict correctly how matter moves? The examples I know of are frame dragging (around rotating BH), shifting of light paths, shifting orbits of planets.
But does Newton's law really predict the magnitude of gravity accuratly? How...
Homework Statement
Two forces act on an object of mass 2.5kg; force F1 that is directed alont the +x-direction and has magnitude of .50N and force F2 that points at a 45 degree angle in the +y and -x quadrant and has magnitude 2.0N. Find the additional force, if any such that the object will...
Homework Statement
A person weighing 55kg jumps off of a bridge with a bungee cord attached. The problem seeks to find the bungee cords Force vector when the acceleration is 7.8m/s2 in the downward direction.
m = 55kg
a1 = g = 9.8m/s2
To find:
F1 when a2 = 7.8m/s2 downward.
I've...
Homework Statement
These are all true/false questions.
1. The acceleration of an object is same in all inertial reference frames.
2. The work required to lift a mass one meter depends on the speed at which it is raised..
3. The work done by a constant force acting on an object is...
Homework Statement
Consider a particle of mass m whose motion starts from rest in a constant gravitational field. If a resisting force proportion to the square of the velocity (i.e. kmv^2) is encounterd, show that the distance s the particle falls in accelerating from v0 to v1 is given by...
In another thread a discussion arose about the interpretation of derivatives. For example acceleration is the time derivative of velocity.
Obviously, in the strictly mathematical sense: in relativistic physics and classical physics alike acceleration is the time derivative of velocity...
Homework Statement
Question 1: Is Ohm's Law (V = IR) invariant under Galilean transformations?
Question 2: Model the Earth as an ellipsoid or a spheroid, and find the lowest order correction to the inverse square law at points inside and outside the Earth's surface.
Homework Equations
--...
I'm reading A Brief History of Time by Stephen Hawking and he says that "gravitational effects should travel with infinite velocity" if an object is moved and therefore the gravitational force between them is instantly changed. this gravitational force then moves faster than the speed of light...
I am trying to simulate a square object affected by a force in two dimensions. I can break up the force vector into a vector whose extension intersects the center of gravity for translation and a vector perpendicular to that for rotation. My question is: how does this rotational vector relate...
I'm trying to find a divergenceless vector field based on its curl, and discovered that I could use a http://en.wikipedia.org/wiki/Helmholtz_decomposition" , and the article I found on this didn't make much sense to me.
First, can someone confirm that the dimension referred to in the...
I'm trying to find a divergenceless vector field based on its curl, and discovered that I could use a http://en.wikipedia.org/wiki/Helmholtz_decomposition" , and the article I found on this didn't make much sense to me.
First, can someone confirm that the dimension referred to in the...
Homework Statement
This question is a slightly customised version of Q18(a) P212 of Schutz
Prove that
G_{\alpha \beta} + \Lambda g_{\alpha \beta} = 8 \pi T_{\alpha \beta}
in the Newtonian limit reduces to
\nabla^2 \phi = 4\pi \rho + \Lambda
(I found this result in another text...
What exactly was wrong with Newtons gravity. I understan that GR says that gravity is the curveture of space and time. However if Newton was wrong wouldn't that mean that F= GMm/d^2 is actualy wrong?
Would someone please help me in thinking the following out:
I was taught that the Newtonian gravitational potential was given as -Gm/r; and when examining a sphere of uniform density ρ and radius r, then at any point x ≤ r (within the sphere), m would refer to the effective mass of an...
I'd appreciate any explanations and maybe an available source that discusses how and why time is relatively more curved than space. Is there is particular source for time curvature in the stress/energy/momentum tensor?? Thank you.
Homework Statement
Given
if:
(1) Fsm + Fem = Mm x Ams
(2) Ams = Ame + Aes
(3) Res ~= Rms
Show that (4) Fem ~= Mm x Ame
Where:
'Fsm' is the force between the sun and moon, 'Fem' the force between Earth and moon, etc.
'Mm' is the mass of the moon, 'Ams' the accelleration of the...
What are the factors that affect viscosity of incompressible Newtonian fluid?
Here is what I think:
Temperature:
When we increase the temperature of a fluid (controlled volume) the frequency ofintermoleculer collisions increases. Does this mean viscosity decreases? And if so, does...
I seem to recall reading a post a long time ago (that I cannot find) that gravity in the Newtonian limit (eg the Solar system) can be completely explained in terms of gravitational time dilation alone.
In his book, Gravity from the Ground up, Schutz argue that All of Newtonian gravitation is...
I've recently been looking at the way in which pressure terms contribute to the Komar expression for the total energy in GR and I've been trying to understand the Newtonian equivalent.
I found something which surprised me, and I'm wondering if it's well-known:
If you take a couple of masses...